基于RTLinux构建机载SAR实时成像处理器嵌入式控制系统

面向地学处理的机载SAR实时成像处理器由一组连接在工业总线上的数据处理板和一个嵌入式主控子系统构成，成像处理器的总体设计对主控系统的实时性，稳定性及可扩展性提出了严格的要求，比较了传统的嵌入式工业控制系统的设计方法，设计并实现一个基于廉价的PC与RTLinux的主控系统，分析了主控系统的两个重点；DSP宿主环境和RTLinux下的混合任务集，并通过给出一个RTLinux与Linux调度精度和误差的对比试验及其结果，证明了基于RTLinux的主控系统对支持细粒度调度方面的优越性。

A Novel Solution of Embedded Host Controller in Real-Time SAR Imaging Systems

The aircraft real-time SAR imaging system is fixed on the plane, and consists of several embedded signal processing boards and a host computer connected by CPCI industrial bus and CAB bus of Coreco, Inc The host computer plays a crucial role in the whole system, responsible for real-time data sampling, storing and displaying, and the most important, the host module must provide a firm real-time computing environment to guarantee the priority-base scheduling of these tasks Instead of using readily available proprietary DSP packages and expensive commercial real-time operating systems (RTOS) such as QNX or VxWorks, an alternative solution is investigated: using a low cost PC and RT-Linux-a compact real-time extension to Linux to construct the host module of SAR imaging system The architecture of the host module is introduced, and several essential aspects of the design are addressed: a novel scalable hierarchal communication framework between multi-DSP and host module and a hybrid task set under RT-Linux, which consists three hard real-time periodical tasks and several soft real-time tasks The real-time mechanism of RT-Linux is analysed In order to illustrate the feasibility of RT-Linux based solution, a set of experiments to decide the dispatch (scheduling) resolution of both Linux and RT-Linux are constructed and the results of comparison are given with figures